bolens



NITED STATES JOHN GILSON AND HARRY WFBOLENS, OF PORT 'WASI-IINGTON, IVISOONSIN, ASSIGNORS TO THE GILSON hlANUFAGTURING COMPANY, OF SAME PLACE.

CHAIR.

SPECIFICATION forming part of LettersPatent No. 562,387, dated June 23, 1896.

Application filed December 2 1894. Serial No. 532,760. (No model.)

To aZZ whom it may concern:

Be it known that we, JOHN GILsON and HARRY W. BOLENS, citizens of the United States, and residents of PortIVashington, in

5 the county of Ozaukee and State of W'isconsin, have invented certain new and useful Improvements in Chairs; and we do hereby declare that the following'is a full, clear, and exact description thereof.

Our invention relates to that class of chairs or analogous devices having vertically-adjustable seat-spindles, as well as to pivotal seats, whether the latter be employed in connection with such spindles or otherwise; and said invention consistsin certain peculiarities of construction and combination of parts hereinafter specified with reference to the accompanying drawings and subsequently claimed.

In the drawings, Figure 1 represents avertical transverse section of assembled parts in one style of chair-iron that embodies the various details of our invention; Fig. 2, an elevation of the same; Figs. 3 and 4, horizontal sections respectively taken on lines 3 3 and a at of Fig. 1, and Fig. 5 an elevation of a portion of a longitudinally-grooved screw-spindle that constitutes a detail of one feature of our invention.

Referring by letter to the drawings, A represents a chair-base casting having a smooth bore provided with a spline b for engagement with a longitudinal groove 0 in a screwthreaded spindle B, that has free play in said bore.

As herein shown, a nut O engages the spindle B above the base-casting A and an annular flange d of the nut is opposed by a guard e, projecting from the adjacent face of said 0 base-casting. This guard acts to prevent the nut and spindle from being lifted up away from the base-casting. Although the nut is shown above the base-casting, it would be no departure from the invention to arrange it below the same, and in such a case the guard would be correspondingly arranged to keep said nut in working position.

As herein shown, the nut C may be provided with a hand-wheel D to facilitate its rotation, and incidental to this rotation the spindle B will have a direct longitudinal adjustment because of the engagement of the spline and groove above specified.

To prevent the spindle working down, in* cidental to movement of a person occupying the chair of which said spindle forms a part, the opposing ends of the nut and base cast ing are waved, the elevations of one engaging the depressions of the other to thereby lock said nut against automatic rotation, this being an important feature of the structure thus far described.

In order to obtain the best results, it is necessary that the casting present a series of waves arranged on a circle and that the nut present a like series and arrangement of waves that interlock with those of said casting.

The spindle herein shown has its upper end provided with a socket for a pivot E, that depends from the seat-iron F, and the chamber 7, shown in communication with the socket, may serve as a receptacle for pivot-lubricant.

As shown in the drawings and above specified, the opposing ends of the adj usting-nut and base-casting are waved, the former of these parts being above the other, but in case of reversal the waving would be preferably transferred to the nut-flange d and guard c, this being a structural variation not involv ing any departure from that feature of the invention that contemplates prevention of automatic rotation on the part of the aforesaid nut.

IIaving'now fully described our invention, what we claim as new, and desire to secure by Letters Patent, is-

l. A chair-base casting presenting a waved annular surface, a longitudinally-gr0oved screw-spindle splined in the casting, and a nut on the spindle presenting a waved annular surface in opposition to that of said casting.

2-. A chair-base casting presenting awaved annular surface, a longitudinally-grooved screw-spindle s plined in the casting, a nut on the spindle presenting a waved annular surface in opposition to that of said casting, and suitable means for limiting longitudinal play of the nut.

3. A chair-base casting presenting a waved annular surface, a longitudinallygrooved screw-spindle splined in the casting, anut on the spindle presenting a waved annular surface in opposition to that of saidoasting, a of Wisconsin, in the presence of two Witflange extending from the nut, and a guard nesses.

on said casting arranged to overlap the nut- JOHN GILSON.

flange. HARRY WV. BOLENS. 5 In testimony that We claim the foregoing Witnesses:

We have hereunto set our hands,at Port Wash- WVM. AHLHAUSER,

ington, in the county of Ozaukee and State L. EGHART. 

